End opening box with self-locking cover and blank for forming the same



Nov. 26, 1963 s. R. MARTIN 3,1

END OPENING BOX WITH SELF-LOCKING COVER AND BLANK FOR FORMING THE SAME' Filed Oct. 50, 1961 3 Sheets-Sheet l m i J I Fig 3 2 i INVENTOR- x Spencer R. Martin Fig. 2 fl QM HIS ATTORNEY Nov. 26, 1963 s. R. MARTIN 3,112,058

END OPENING BOX WITH SELF-LOCKING COVER AND BLANK FOR FORMING THE SAME Filed Oct. 30. 1961 '3 SheetsSh'eet2 INVENTOR. Spencer R. Martin H/S ATTORNEY Nov. 26, 1963 s. R. MARTIN ,058

END OPENING BOX WITH SELF-LOCKING COVER AND BLANK FOR FORMING THE SAME Filed 001;. 50, 1961 3 Sheets-Sheet 3 -m I I 2 INVENTOR. m x Spencer 1?. Mar/in BY m HIS ATTORNEY United States Patent ice 3,112,058 END OPENING BOX WITH SELELOCKING COVER AND BLANK FOR FORMING THE SAME Spencer R. Martin, Niagara Falls, N.Y., asstgnor to The Carborundum Company, Niagara Falls, N.Y., a corporation of Delaware Filed Oct, 30, 1961, Ser. No. 148,521 9 Claims. (Cl. 229-36) This invention relates to an end opening box with a self looking cover. It is useful for containing sander discs. Such discs comprise a backing made of paper, cloth, vulcanized fiber, or other suitable material and abrasive grains bonded to the backing by resin or other suitable binder. The discs are usually round and have a hole in the center for mounting them on a grinding fixture. When a number of such discs are contained in a box and stored for a considerable length of time, due to tendency to curl, they exert a pressure on the cover of the box and sometimes cause it to fly or pop open. Thereafter, the discs, being unrestrained, curl to a greater extent. Curling of the discs to any substantial extent, of course, is objectionable.

The present invention provides an end opening box with a self locking cover. When the cover is closed in folding the box from a blank, the folding of the cover into place automatically locks it into position so that it cannot fly open due to the pressure exerted upon it by the curling of the discs. Thus, by maintaining the cover locked, the extent of curling of the discs is limited. The invention also relates to a blank from which the box is formed by folding.

In the-accompanying drawings which illustrate a preferred embodiment of the invention:

FIGURE 1 is a plan view of a box blank;

FIGURE 2 is a plan view of the box completely closed;

FIGURE 3 is a vertical section, on an enlarged scale, taken on the line II=IIII of FIGURE 2;

FIGURES 4 through 8 are isometric views illustrating diiferent successive steps of folding the blank into a closed box in which the cover is locked in position;

FIGURE 9 is a vertical section, on an enlarged scale, taken on the line IXIX of FIGURE 2; and FIGURE 10 is a vertical section taken on the line XX of FIGURE 9.

Referring now more particularly to the accompanying drawings, and for the present to FIGURE 1, the figure represents a box blank A made of cardboard or other suitable flexible sheet material which when folded along the dot and dash fold lines, hereinafter more particularly referred to, in the sequence of steps hereinafter more fully described, results in a closed box with the cover locked in position.

The blank A has a substantially rectangular bottom panel 2 having sides defined by fold lines '4, 6, 8 and 10. Two side panels 12 are integral with the bottom panel 2, and extend outwardly from the opposite sides 4 and 8 of the bottom panel. Each of the side panels 12 has one or more fold lines 14 extending across it parallel to the fold lines 4 and '8 to divide each of the side panels into an upfold side panel 16 and a downfold side panel 18. The fold lines 14 when single, as shown, are substantially equidistant from the fold lines 4 or 8 and the outer sides 20 of the downfold panels 18. Alternatively, each fold line 14 can consist of a pair of parallel fold lines in approximately the same location with respect to fold lines 4 and 8 and outer sides 20, but spaced apart a distance approximately equal to two thicknesses of the material forming the blank to form a double fold along the top line connecting upfold side panel 16 and downfold side panel 18, so as to form a narrow horizontal or flat connecting strip between the two. Each of the downfold side panels 18 Patented Nov. 26, 1963 has a tab 22 extending outwardly from its side 20. The tabs 22 fit in corresponding slots 24 in the bottom panel 2 when the side panels 12 are folded as shown in FIG- URE 10, thereby maintaining the downfold side panels 18 in fixed relation to the bottom panel 2. Each downfold side panel 18 has a lock tab slot 26 for a purpose hereinafter explained.

An end panel 28 defined by fold line 6, two fold lines 30 and an outer side 32 is integral with the bottom panel 2. Two wings 34 extend from the ends 30 of the end panel 28, the wings being spaced from the upfold side panels 16 by spaces '36. A finger hole 38 is provided in the side 32 of end panel 2 8.

An end panel 40, defined by fold lines 10, 42 and 44, is integral with the bottompanel 2. Two wings 46 extend from the ends 42 of the end panel 40, the wings being spaced from the upfold side panel 16 by spaces 48. A cover panel 50, defined by fold lines 44, 52, 54 and 56, is integral with the end panel 40. Two cover flaps 58 are integral with and extend outwardly from the cover panel 50. The left hand end of each cover flap 58 as shown in FIGURE 1 is curved as indicated at 60 to allow lowering of the cover in folding the blank A into a box as hereinafter explained. Each cover flap 58 is spaced at one end from a wing 46 by a space 62. Each of the cover flaps 58 is provided with a lock tab 64 formed by slitting a portion of each cover flap and pressing the tab out of the plane of the cover flap. The look tabs 64 are received in the lock tab slots 26 of the downfold panels 18 when the blank is folded into a box, thereby locking the cover.

A cover end panel 66, defined by fold lines 54 and 68 and the outer side 70 is integral with and extends from the side 54 of the cover. Two Wings 72 are integral with and extend from the ends 68 of the cover end panel 66, the wings 72 being spaced from the adjacent ends of the cover flaps 58 by spaces 74.

Referring now more particularly to FIGURES 2 through 10, the blank is first folded to the position shown in FIGURE 4, assuming that the bottom panel 2 is supported on a horizontal support or is held in a horizontal posit-ion, by folding upwardly the end panel 40, cover panel 50, cover flaps 58, cover end panel 66 and wings 72, this folding being along the fold line 10, and folding the wings 46 inwardly along the fold lines42. This places the parts in the position shown in FIGURE 4.

The two side panels 12 are then folded upwardly along fold lines 4 and '8 to provide the upfold side panels 16 and then the downfoldside panels 18 are folded downwardly over the wings 46 along fold lines 14. The tabs 22 on the downfold side panels are then inserted into the 'slots 24 in the bottom panel 2, thereby retaining the downfold side panels in a fixed relation to the bottom panel. The parts are then in the positions shown in FIGURE 5.

To place the parts in the positions shown in FIGURE 6, the two cover flaps 58 are first folded inwardly along the fold lines 52 and 56 and then the cover panel 50, cover flaps 58, cover end panel 66 and wings 72 are folded downwardly and forwardly along the fold line 44. In this downward and forward movement, the lock tabs 64 align themselves with the lock tab slots 26 and due to the fact that the lock tabs extend upwardly and outwardly from the cover flaps 58, the lock tabs engage in the lock tab slots as shown in FIGURES 3 and9, whereby the cover panel 50 automatically becomes locked in position. The parts are then in the position shown in FIGURE 6 with the cover panel locked in position.

The two wings 34 on the end panel 28 are then folded upwardly and inwardly along fold lines 30 to assume vertical positions and then the end panel 28 is folded upwardly and rearwardly along the fold line 6 thereby forcing each of the wings 34 into the space 76 between an upfold side panel 16 and a downfold side panel 18 as shown in FIGURE 3. This places the parts in the positions shown in FIGURE 7.

The wings 72 on the cover end panel 66 are then folded inwardly and downwardly along the fold lines 68 and the cover end panel is then folded downwardly and rearwardly along the fold line 54 thus forcing the wings 72 into the spaces 76, each wing 72 being located between an upfold side panel 16 and a wing 34 of the end panel 28, as shown in FIGURE 3.

In the operation of folding the box from the blank the sequence of folding steps can be varied in numerous obvious manners from that shown in the series of FIG- URES of the drawings. For example, the preferred practise, after the blank has been brought to the folded condition as shown in FIGURE 5, is to fold the two wings 34 on the end panel 28 upwardly and inwardly along fold lines 30 to assume vertical positions and then the end panel 28 is folded upwardly and rearwardly along the fold line 6 thereby forcing each of the wings 34 into the space 76 between an upfold side panel 16 and a downfold side panel 18 as shown in FIGURE 3. This is done before the top panel 50 is folded down to close the box. At this step of the folding operation, the partially folded box is ready to either stack for future use, or is ready for facile loading with its contents of abrasive discs from the top, or only remaining open, part of the box, after which the top panel 50, cover flaps 58, cover end panel 66 and wings 72 are folded in the same manner as herein above already described to close the box and lock the cover in position.

In opening the end of the box to remove a disc or other article contained therein, the cover end panel 66 is folded forwardly and upwardly along the fold line 54 thus removing the wings 72 from the space 76. Then the end panel 28 is folded downwardly and forwardly along the fold line 6 to a substantially horizontal position thus withdrawing wings 34 from the spaces 76. This may be accomplished easily by inserting a finger into the finger hole 38 and exerting the necessary force. The parts are then in the positions shown in FIGURE 6 in which the cover panel 59 remains locked in position.

The invention is not limited to the preferred embodimeat, but may be otherwise embodied or practiced within the scope of the following claims.

I claim:

1. A blank made from flexible sheet material adapted for folding into an end-opening box having a self-locking cover wherein said cover is locked in position solely by the engagement of a lock tab element in a lock tab slot element comprising a substantially rectangular bottom panel defined by fold lines, two side panels integral with said bottom panel and extending along each of two opposite sides of said bottom panel for substantially the length of the side, each of said side panels being divided into an upfold side panel and a downfold side panel by a fold line extending substantially parallel to the fold line separating the side panel from the bottom panel a tab extending outwardly from the outer side of each downfold side panel, said bottom panel being provided with two corresponding slots for receiving said tabs, two end panels integral with said bottom panel and extending along each of two opposite ends of said bottom panel for substantially the length of the end, a cover panel integral with one of said end panels, two cover flaps integral with said cover panel and extending along each of two opposite sides of said cover panel, and cooperating cove-r panel locking means including a lock tab element and a lock tab slot element, one of said elements being on at least one of said cover flaps and the other of said elements being on at least one of said downfold side panels.

2. A blank according to claim 1, wherein the cooperating cover panel locking means includes a lock tab formed 41 in each of said cover flaps and a corresponding lock tab slot formed in each of said downfold side panels.

3. A blank according to claim 1, wherein the end panel which is integral with said cover panel has a wing extending from each of its ends, said wings lying at least in part between but being separate from said cover flaps and said upfold side panels.

4. A blank made from flexible sheet material adapted for folding into and end-opening box having a self-locking cover wherein said cover is locked in position solely by the engagement of a lock tab element in a lock tab slot element, comprising a substantially rectangular bottom panel defined by fold lines, two side panels integral with said bottom panel and extending along each of two opposite sides of said bottom panel for substantially the length of the side, each of said side panels being divided into an upfold side panel and a downfold side panel by a fold line extending substantially parallel to the fold line separating the side panel from the bottom panel, a first end panel integral with said bottom panel and extending along an end of said bottom panel for substantially the length of the end, a wing extending from each end of said first end panel and being spaced from an end of said upfold side panel, a second end panel integral with said bottom panel and extending along the end of said bottom panel opposite said first end panel for substantially the length of the end, a wing extending from each end of said second end panel and being spaced from said upfold side panel, a cover panel integral with said second end panel, two cover panel flaps integral with said cover panel and extending along each of two opposite sides of said cover panel, the ends of said cover flaps being spaced from the wings on said second end panel, a cover end panel integral with said cover panel, a wing extending from each end of said cover end panel and spaced from said cover flaps, a lock tab formed in each of said cover flaps and a corresponding lock tab slot formed in each of said downfold side panels.

5. An end opening box with self locking cover made from a single piece blank of flexible sheet material cut and folded into said box, which comprises a substantially rectangular bottom panel defined by fold lines, two side panels integral with said bottom panel and extending along each of two opposite sides of said bottom panel for substantially the length of the side, each of said side panels being divided into an upfold side panel and a downfold side panel by a fold line extending substantially parallel to the fold line separating the side panel from the bottom panel, two end panels integral with said bottom panel and extending along each of two opposite ends of said bottom panel for substantially the length of the end, a cover panel integral with one of said end panels, two cover flaps integral with said cover panel and extending along each of two opposite sides of said cover panel, said cover flaps being separated from said cover panel by fold lines, the end panel which is integral with said cover panel having two wings extending from the ends of the end panel, said wings being separated from said end panel by fold lines, each of said side panels being folded upwardly along the fold lines separating the side panel from the bottom panel to form an upwardly extending upfold side panel and then being folded downwardly and inwardly along the fold line dividing it into an upfold side panel and a downfold side panel to form a downwardly extending downfold side panel, each of said side panels embracing a wing on said end panel, each of said downfold side panels being maintained in fixed relation to said bottom panel, and cooperating cover panel locking means including a lock tab element and a lock tab slot element, one of said elements being on at least one of said cover flaps and the other of said elements being on at least one of said downfold side panels.

6. A box according to claim 5, wherein the cooperating cover panel locking means includes a lock tab formed on each of said cover flaps and a corresponding lock tab slot formed in each of said downfold side panels.

7. An end opening box with self locking cover made from a single piece blank of flexible sheet material cut and folded into said box, which comprises a substantially rectangular bottom panel defined by fold lines, two side panels integral with said bottom panel and extending along each of two opposite sides of said bottom panel for substantially the length of the side, each of said side panels being divided into an upfold side panel and a downfold side panel by a fold line extending substantially parallel to the fold line separating the side panel from the bottom panel, a first end panel integral with said bottom panel and extending along an end of said bottom panel for substantially the length of the end, a wing extending from each end of said first end panel, said wings being separated from said first end panel by fold lines, a second end panel integral with said bottom panel and extending along the opposite end of said bottom panel for substantially the length of the end, a wing extending from each end of said second end panel, said wings being separated from said second end panel by fold lines, a cover panel integral with said second end panel, two cover panel flaps integral with said cover panel and extending along each of two opposite sides of said cover panel, said cover fiaps being separated from said cover panel by fold lines, a cover end panel integral with said cover panel, a wing extending from each end of said cover end panel, said wings being separated from said cover end panel by fold lines, each of said side panels being folded upwardly along the fold line separating the side panel from the bottom panel to form an upwardly extending upfold side panel and then being folded downwardly and inwardly along the fold line dividing it into an upfold side panel and a downfold side panel to form a downwardly extending downfold side panel, each of said side panels embracing a wing on said second end panel, each of said downfold side panels being maintained in fixed relation to said bottom panel, a lock tab formed in each of said cover flaps and a lock tab slot formed in each of said downfold side panels, said lock tabs and lock tab slots being in engagement with each other.

8. An end opening box with self locking cover made from a single piece blank of flexible sheet material cut and folded into said box, which comprises a substantially rectangular bottom panel defined by fold lines, two side panels integral with said bottom panel and extending along each of two opposite sides of said bottom panel for substantially the length of the side, each of said side panels being divided into an upfold side panel, and a downfold side panel by a fold line extending substantially parallel to the fold line separating the side panel from the bottom panel, a first end panel integral with said bottom panel and extending along an end of said bottom panel for substantially the length of the end, a wing extending from each end of said first end panel, said wings being separated from said first end panel by fold lines, a second end panel integral with said bottom panel and extending along the opposite end of said bottom panel for substantially the length of the end, a wing extending from each end of said second end panel, said wings being separated from said second end panel by fold lines, a cover panel integral with said second end panel, two cover panel flaps integral with said cover panel and extending along each of two opposite sides of said cover panel, said cover flaps being separated from said cover panel by fold lines, a cover end panel integral with said cover panel, a wing extending from each end of said cover end panel, said wings being separated from said cover end panel by fold lines, each of said side panels being folded upwardly along the fold line separating the side panel from the bottom panel to form an upwardly extending upfold side panel and then being folded downwardly and inwardly along the fold line dividing it into an upfold side panel and a downfold side panel to form a downwardly extending downfold side panel, each of said side panels embracing a wing on said second end panel, each of said downfold side panels being maintained in fixed relation to said bottom panel, a lock tab formed in each of said cover flaps and a lock tab slot formed in each of said downfold side panels, said lock tabs and lock tab slots being in engagement with each other, the wings on said first end panel being folded along the fold lines separating said wings from said first end panel and being located in the space between said upfold side panel and said downfold side panel, the wings on said cover end panel being folded along the fold lines separating said wings from said cover end panel and being located in the space between said upfold side panel and said downfold side panel.

9. A box according to claim 8, wherein the parts of the box are so arranged and dimensioned that in a vertical section taken through the box the parts are located as follows from the inside to the outside of a side wall of the box: first, a cover panel flap; second, a downfold side panel; third, a wing on said first end panel; fourth, a wing on said cover end panel; fifth, an upfold side panel.

References Cited in the file of this patent UNITED STATES PATENTS 1,801,389 Rumpel Apr. 21, 1931 2,319,919 Clarke May 25, 1943 2,464,904 Tomarin Mar. 22, 1949 2,707,587 Wittstein May 3, 1955 

5. AN END OPENING BOX WITH SELF LOCKING COVER MADE FROM A SINGLE PIECE BLANK OF FLEXIBLE SHEET MATERIAL CUT AND FOLDED INTO SAID BOX, WHICH COMPRISES A SUBSTANTIALLY RECTANGULAR BOTTOM PANEL DEFINED BY FOLD LINES, TWO SIDE PANELS INTEGRAL WITH SAID BOTTOM PANEL AND EXTENDING ALONG EACH OF TWO OPPOSITE SIDES OF SAID BOTTOM PANEL FOR SUBSTANTIALLY THE LENGTH OF THE SIDE, EACH OF SAID SIDE PANELS BEING DIVIDED INTO AN UPFOLD SIDE PANEL AND A DOWNFOLD SIDE PANEL BY A FOLD LINE EXTENDING SUBSTANTIALLY PARALLEL TO THE FOLD LINE SEPARATING THE SIDE PANEL FROM THE BOTTOM PANEL, TWO END PANELS INTEGRAL WITH SAID BOTTOM PANEL AND EXTENDING ALONG EACH OF TWO OPPOSITE ENDS OF SAID BOTTOM PANEL FOR SUBSTANTIALLY THE LENGTH OF THE END, A COVER PANEL INTEGRAL WITH ONE OF SAID END PANELS, TWO COVER FLAPS INTEGRAL WITH SAID COVER PANEL AND EXTENDING ALONG EACH OF TWO OPPOSITE SIDES OF SAID COVER PANEL, SAID COVER FLAPS BEING SEPARATED FROM SAID COVER PANEL BY FOLD LINES, THE END PANEL WHICH IS INTEGRAL WITH SAID COVER PANEL HAVING TWO WINGS EXTENDING FROM THE ENDS OF THE END PANEL, SAID WINGS BEING SEPARATED FROM SAID END PANEL BY FOLD LINES, EACH OF SAID SIDE PANELS BEING FOLDED UPWARDLY ALONG THE FOLD LINES SEPARATING THE SIDE PANEL FROM THE BOTTOM PANEL TO FORM AN UPWARDLY EXTENDING UPFOLD SIDE PANEL AND THEN BEING FOLDED DOWNWARDLY AND INWARDLY ALONG THE FOLD LINE DIVIDING IT INTO AN UPFOLD SIDE PANEL AND A DOWNFOLD SIDE PANEL TO FORM A DOWNWARDLY EXTENDING DOWNFOLD SIDE PANEL, EACH OF SAID SIDE PANELS EMBRACING A WING ON SAID END PANEL, EACH OF SAID DOWNFOLD SIDE PANELS BEING MAINTAINED IN FIXED RELATION TO SAID BOTTOM PANEL, AND COOPERATING COVER PANEL LOCKING MEANS INCLUDING A LOCK TAB ELEMENT AND A LOCK TAB SLOT ELEMENT, ONE OF SAID ELEMENTS BEING ON AT LEAST ONE OF SAID COVER FLAPS AND THE OTHER OF SAID ELEMENTS BEING ON AT LEAST ONE OF SAID DOWNFOLD SIDE PANELS. 